In the latest U.S.-Mexico Obama Justice Department corruption saga, the New York Times is reporting Drug Enforcement Administration undercover agents have been laundering millions of dollars in Mexican Cartel profits in an effort to "catch the big fish," just as they tried to do by allowing thousands of guns to walk during Operation Fast and Furious.

Undercover American narcotics agents have laundered or smuggled millions of dollars in drug proceeds as part of Washington’s expanding role in Mexico’s fight against drug cartels, according to current and former federal law enforcement officials.

The agents, primarily with the Drug Enforcement Administration, have handled shipments of hundreds of thousands of dollars in illegal cash across borders, those officials said, to identify how criminal organizations move their money, where they keep their assets and, most important, who their leaders are.

They said agents had deposited the drug proceeds in accounts designated by traffickers, or in shell accounts set up by agents.

The officials said that while the D.E.A. conducted such operations in other countries, it began doing so in Mexico only in the past few years. The high-risk activities raise delicate questions about the agency’s effectiveness in bringing down drug kingpins, underscore diplomatic concerns about Mexican sovereignty, and blur the line between surveillance and facilitating crime. As it launders drug money, the agency often allows cartels to continue their operations over months or even years before making seizures or arrests.

Another former agency official, who asked not to be identified speaking publicly about delicate operations, said, “My rule was that if we are going to launder money, we better show results. Otherwise, the D.E.A. could wind up being the largest money launderer in the business, and that money results in violence and deaths.”

Those are precisely the kinds of concerns members of Congress have raised about a gun-smuggling operation known as Fast and Furious,